The patterns change with age, one reason that early-to-rise youngsters evolve into hard-to-wake teens. Morning light resets the rhythm. By evening, levels of a hormone called melatonin begin to surge, ...

Instead, it could be the dawn phenomenon, a rise in early morning blood sugar levels that can occur in people with diabetes. It typically happens between 2 a.m. and 8 a.m. and is believed to be ...